Work vehicles, including agricultural tractors and construction equipment, have long been provided with engine compartments, and in some cases additional compartments for other uses, which are often desired to be at least partially covered for protection from dust, debris, weather, theft, etc. Engine compartments may be covered to also contain noise and to route cooling air flow. Such compartments are generally kept covered by hoods in normal use of the vehicle and in storage, but must be opened to provide access for periodic maintenance and inspection and for repairs.
Hoods are generally too heavy to be readily removed and set aside, and so are provided with opening, or "lift", mechanisms. Many such lift mechanisms comprise simply pivots, or hinges, at one end of the hood, often including a torsion spring or gas spring to balance the weight of the hood when in an opened position. Some mechanisms, with or without a balancing spring, also include a support rod for propping the raised hood up in its opened position. Such mechanisms reposition a hood in a manner which provides substantially full access to the interior of the compartment at the end at which the hood has been raised, but access at the pivot end which is often marginal. Such hoods must then be removed and set aside, often with a lift truck or a crane, for work to be performed on an item within, and at the hood pivot end of, the compartment.
Other types of hood opening mechanisms are known, including one in which a hood slides longitudinally upon rollers riding in a track and does not lift; while this mechanism provides reasonably full access to the interior of the compartment, it is costly and requires an inordinately long garage stall to accommodate it. Another type of mechanism includes a four-bar linkage which both pivots and translates the hood in an arcuate path of motion. These are relatively effective, but have not heretofore included a backup latch which is both actuatable in the closed position with a single control device and supported in the opened position with the same control device.
There has been, therefore, a longstanding need for a hood lift mechanism which repositions the hood in a manner which provides substantially full access to items within a compartment, and which includes a simple apparatus for both backing up a primary hood latch and supporting the hood in its opened position.